Adjustable fire bridge for furnaces having movable grates



March 18 1924.

A. W. BENNIS ADJUSTABLE FIRE BRIDGE FOR FURNACES HAVING MOVABLE GRATES Filed Jan. 2 1917 INVENTOR AW. Bennie March 18 1924. 1,487,527

A. W. BENNIS ADJUSTABLE FIRE BRIDGE FOR FURNACES HAVING MOVABLE GRATES Filed Jan. 27 1917 4 Sheets-Sheet. 2

557 231317 AW. BenniS March"'18 1924. '1;487;52"7 A. w. BENNIS I ADJUSTABLE FIRE BRIDGE FOR FURNACES HAVI NG MOVABLE GRATES Filed Jan; 27 1917 4 Sheets-Sheet 3 4 Sheets-Sheet 4 A. w. BENNIS Filed Jan. 27,

March 18 1924a ADJUSTABLE FIRE BRIDGE FOR FURNACES HAVING MOVABLE GRATES s L I r n m H H .0 n. v... WJ 6 l i JB .n r T u u x w n u n" A n I m? -iliii: mu l mm M Hl nHP L IHHHHHWI HhHl l PHL PJHHHHHHl HnU l l l l hn O n: m .m n m a 1 O. :m u u a 2- u g u "u "n a 2 n u n w m a u n y N 1 V n .m u 1 m u 6 7 A m Patented ALFRED WILLIAM BENNIS, F BOLTON, ENGLAND.

ADJUSTABLE FIRE BRIDGE FOR FURNACES HAVING MOVABLE GRATES,

Application filed January 27, 1917. Serial 110.144,.994,

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3,1921, 41 STAT. L 1313.

To all whom it may concern:

Be it known that I, ALFRED WILLIAM BEN- ms, subject of the King of Great Britain, residing at Little Hulton, Bolton, in the a county of Lancaster, in the Kingdom of En land, have invented certain new and use Improvements in Adjustable Fire Bridges for Furnaces Having Movable Grates, for which I have filed an application in England, No. 611, January 14, 1916,

Patent No. 103,315, January 15, 1917, and of which the following is a specification.

' This invention relates to improvements in furnaces of the ty e in which an adjustable 16 bridge is arranged over amoving grate to allow of clinker, ash and the like refuse to be automatically discharged from the furnace.

According to the present invention, the movin grate extends throu h or partially throng the backwall of the urnace, preferably so that the back shaft and its bearings are outside the furnace. J

In certain constructions the grate extends through the bridge wall and a chamber is formed behind the bridge wall so that the operationof removing the clinker either intermittently or continuously by mechanical means can be carried on without stopping the efiicient working of the chain grate and theboiler. v

Suitable air sealing arrangements are provided to prevent coldair reaching the furnace or to prevent an excess of air reaching the furnace round the adjustable bridge or over the same from the outside The invention is more particularly described with reference to the accompanying drawings, in which 4a Figure 1 is a side elevation in part sec- 4 tion of a pivoted and balanced bridge placed outside a marine type water tube boiler.

FigureQ is an elevation taken at the left hand side of the furnacewhilst Figure 2 is a transverse section on the right hand side of the furnace.

' Figure 3 is a plan view of the furnace.

Now referring to the drawings, in one form of constructiongas shown in Figures 50 1, 2 and 3, the chain'grate extends through the rear wallof a marine boiler furnace part of the rear wall bein shown at 9.

The chain grate 1 is supporte by spaced rollers 4 and revolves over the rear drum 2 mounted on the rear axle 3,-which is placed in this case outside the furnace therebyproviding easy access to the bearings.

A pivoted bridge 10 is formed ofbrick:

disposed as to'support the refractory brick. The pivoted bridge 10'has pivots 11 which carry the lever or levers 13 which in turn .work and suitable metal, the metal being so carry the balance weights 14 by means 'ofthe hook rod 15. Any other form of lever and balance may be used as convenient, such as a chain, pulley and balanceweight, or a chain or rope and winch.

Thepivot is supported orra bearing 12 carried on the side'frame 21.

The present construction shows the frame 21 going right down to the ground, but it is obvious of course that the bridge might be supported by the chain grate frame 5 itself should it be found desirable. The chain grate frame 5 is shown supportedby wheels 6 and rear axle 7.

A hopper 17 isshoivn designed to-carry away the ashes and clinker which fall over the end of the grate into an underground conduit, but it is obvious that small tubs may be placed underneath the end of the grate, or the clinker can be caused to fall into a suitable conveyor or other'apparatus designed /to mechanically or pneumatically carry away the clinker and ash as itv falls over the end of the grate.

Side seals 20 hinged in a suitable manner areprovided to prevent excessair leaking round the sides of the pivoted-bridge. These are shown hinged but it is obv1ous there are many ways the desired result.

In order to prevent air leaking in over the top of the pivoted bridge, a swing sealing plate 18 is provided which may be hinged in such a way as to present a close joint all the way along the top, but it. is preferred to use a sealing hook as shown in the drawing with a trou h 19 which, when filled with sand or the ike forms an eflicient' air seal. v

The plate 18 is so weighted'and the positionof the hinge is so arranged that a sli ht pivoted blii gen pressure is exerted against the to form an eflicient seal,

The rear wall of the furnace may be arched where the grate gees through it, or may be supperted as shown in Figure 1 by of pivoting these effect means of an angle plate 8, the lower portion of which may be protected by another plate in case of overheating.

As the grate 1 travels rearwards carrying the clinker and ash with it any cinders or unburnt' fuel which remain on top of the clinker, slag and other'refuse may be sired, from above the seal plate 18 to the ground, and suitable doors arranged to obtain access to the various parts. In this way 'the boiler would be suitable for use with forced draught.

A bar 22 is placed behind the grate resting in slots or holes formed in the side frames so that if any very large clinkers form on the grate and any difiiculty' is experienced in getting them off, the attendant may rest a heavy slicer on top of the bar 22 and so facilitate his work in slicing the grate. This bar will also be found useful in slicing the sides of the grate when clinker which sticks to the brick wall of the furnace may be removed.

By having a sight hole at the side of the furnace and a lever brought adjacent thereto from the pivot 11 the attendant may observe the rear part of the fire and adjust the height of the bridge 10 to suit existing conditions. If he has any large lumps of clinker to get rid of momentarily he can raise the. bridge 10 until they are passed and then lower it again.

The pivot 11 may be placed insuch a position that the horizontal thrust of the clinker or material being carried by the chain grate will be sufliciently opposite the centre of the pivot 11 so that it will not either raise or lower the bridge 10 by its thrust, or suitable stops or fastenings may be arranged to prevent the bridge from moving. The construction as shown is however preferred as if a large wedge shaped piece of material gets under the bridge it will not cause a jam but merely raise it and pass underneath it.

As the grate 1 travels rearwards carrying the clinker and ash with it, any cinders or unburnt fuel which remain on the top of the clinker, slag and other refuse may be shaved ofi? by the lower portion of the lifting bridge 10 and will then pile up inside the grate forming a seal.

I declare that what I claim is 1'. A furnace comprising walls, a movinggrate extending through the back wall, an adjustable bridge, means guiding the bridge vertically, a swinging plate preventing leakage of air about said brid e, walls partially surrounding the rear portion of the grate and forming an approximately airtight enclosure for the rear end of the furnace.

2. A furnace comprising walls, a moving 

